Gas turbine engines are widely used to generate power for numerous applications. A conventional gas turbine engine includes a compressor, a combustor, and a turbine. In a typical gas turbine engine, the compressor provides compressed air to the combustor. The air entering the combustor is mixed with fuel and combusted. Hot gases of combustion are exhausted from the combustor and flow across the blades of the turbine so as to rotate a shaft of the turbine connected to the blades. Some of that mechanical energy of the rotating shaft drives the compressor and/or other mechanical systems.
Temperatures in modern gas turbine combustors may exceed two thousand degrees Fahrenheit. As a result, the mechanical components exposed to these temperatures within the combustor may experience significant thermal stress during operation of the gas turbine, thus significantly reducing the mechanical life of the combustor. In addition, when the gas turbine is operated in an environment in which the ambient temperature of the air entering the compressor is above certain levels, the core engine temperature may rise to an unacceptably high level, thus affecting engine efficiency and possibly decreasing the life of the gas turbine components.
Various methods exist for reducing the temperatures within a gas turbine. For example, one method for controlling the temperature within the combustor of a gas turbine involves passing the air entering the compressor through a chiller at the compressor inlet, thereby decreasing the temperature of the compressed air as it enters the compressor. However, the compressed air temperature provided to the combustor in this manner may not provide sufficient cooling of the mechanical components within the combustor. In addition, this method does not allow for directing the cooled compressed air to the individual components or zones within the combustor. Therefore, an improved gas turbine and a method for operating the gas turbine would be useful.